Molokaʻi’s Lori Buchanan has been working to protect the island from invasive species for over three decades, and last week, one of her worst fears came true.
The first two Coconut rhinoceros beetles were detected on Molokaʻi. They can spread quickly and are highly destructive to palms as well as hala, banana, kalo and more.
“Molokaʻi is the last place that you can have beta repository for all these great perpetual species of genetic integrity of coconut species. And if we let one bug do that to us, then it's just devastating,” said Buchanan.
She is the coordinator of the Molokaʻi subcommittee of the Maui Invasive Species Committee, known as MoMISC.
“Unfortunately, our job is dealing with the worst pests. Our mission is to take care of incipient pest species before they become established. And that's our job, period,” she said. “That's what we're going to do now.”
On April 7, the MoMISC crew found a dead, male CRB in their trap near Kaunakakai Wharf. The following day, a second beetle was discovered about 10 miles to the west - this time, a female. The traps had previously been checked on April 1, with no detections.
"We're taking it very seriously. It's all hands on deck," said Buchanan.
The field crew of three has been monitoring for CRB since 2014, following the first Hawaiʻi detection of the beetle on Oʻahu in 2013.
By 2024, MoMISC had over 40 traps placed across Molokaʻi, including Kalaupapa.
“We knew that it would just be a matter of time before the beetle showed up,” Buchanan explained.
The black traps are about 3.5 feet tall and use pheromones to lure any nearby beetles. Since the detections, the crew has been working overtime to assemble and install more than 30 new traps around the detection areas.
“The public needs to know that early detection traps are not there to actually control the bugs,” explained Buchanan. “They're there to just detect the bugs, and the control work comes in with identifying breeding sites, and that's the most important emergency response right away is to identify if they're laying eggs and we have larvae.”
So far, no larvae have been found, which is good news. But it’s still unclear how the two beetles got to Molokaʻi.
“Was this a hitchhiker? Did it fall off of somebody's truck? Or is it from a breeding site somewhere, and they've come out of the pile and they flew into our trap?”
The detections come after a state ban was established last fall on the import of potential CRB host materials to Molokaʻi.
Buchanan is now looking to expand the crew and infrastructure capacity to tackle the new threat. Along with continuing to monitor for other species, the small crew and on-island resources are spread thin. The island is also still recovering from recent heavy flooding, and Buchanan said that poses extra challenges.
“It's like a perfect storm, right? Everything happened at the same time. So that's why Molokaʻi is really stretched, and that's why I'm trying to address the support capacity and infrastructure for getting emergency response out.”
The MoMISC crew is working in collaboration with agencies like the state Department of Agriculture and Biosecurity, and the County of Maui.
Buchanan urges residents to check for the large, white larvae, which are around 3 inches long, in green waste and mulch piles. Adult CRB, measuring about 2 inches, cause V-shaped cuts in palm fronds and bore holes in the crowns, killing the tree.
It’s important to report any sightings to MoMISC before killing beetles or larvae. Buchanan said proper identification of the pest is critical, as there are other species like the oriental flower beetle, that can look similar. MoMISC crew is also keeping careful records and logging the data using GPS for real-time tracking.
Buchanan said the team has a track record of success using these methods over the past 30 years, playing a critical role in keeping the island free of invasive pests like little fire ants and coqui frog. Through early detection and community reporting, they have caught several coqui frogs that made it to the island, preventing the species’ spread.
Now, there’s a new sense of urgency to protect the island from CRB. She said Molokaʻi’s subsistence lifestyle depends on it.
“We're going to do everything humanly possible to nip this in the bud,” said Buchanan. “And we never give up.”
Reports of possible CRB on Molokaʻi can be made by calling MoMISC at 808-480-8191. Across Hawaiʻi, CRB can be reported to the state pest hotline at 643-PEST.
